Which equation represents a direct linear variation? a. y = x + 3 b. y = x2 c. y = 1/x d. y= 1/5xwhat is the direct linear variation equation for the relationship?   y varies directly with x and y = 4 when x=12a. y = x+8 b. y= 3xc. y= 1/3x     d. y= x-8